Impact of processing conditions on amino acid digestibility of expeller-extracted canola meal for broiler chickens

Canola meal (CM) is reported to have lower crude protein (CP) and lower and more variable amino acids (AA) and digestibility than soybean meal (Khajali and Slominski, 2012). Chemical composition and nutrient digestibility of expeller-extracted canola meal (ECM) for broiler chickens has previously been characterized and compared with solvent extracted canola meal (Woyengo et al., 2010), but the possible impact of processing conditions has not been verified. The present study was conducted to characterize the effect of canola processing conditions on CP and AA digestibility of ECM for broiler chickens. Six ECM samples produced under different seed conditioning temperature (90, 95 or 100 °C) and second press screw torque (low or high) conditions were evaluated in a 3 x 2 factorial arrangement of treatments to determine the effect of processing on apparent and standardised CP and ileal AA digestibility in 24 d-old broilers. The ECM samples were incorporated into semi-purified diets to provide 200 g/kg CP, with each of the 6 canola meal samples supplying the entire CP fraction of the diet. A nitrogen free diet was also fed to determine the endogenous AA flow. Each diet was fed for 5 d to 6 replicate cages of 7 chicks and ileal samples were collected at 24 d.